The present disclosure relates generally to access control systems, and more particularly, to a system and a method to encrypt Magnetic Strip Cards.
The ubiquitous magnetic strip card is widely used in access control applications such as hotel locks. The magnetic strip cards are typically inexpensive to the point of being a disposable device, however, the magnetic strip cards provide only a relatively small amount of storage space, e.g., several hundred bits and it is often desirable for one card to open multiple locks. Since the magnetic strip card is usually encrypted, a common solution is to use the same encryption key throughout the hotel, so each door lock is able to decipher a card and verify access information. However, this may pose a security risk, as one lock's compromise results in all being compromised.
Alternatively, different encryption keys may be used for each lock. However, the relatively small amount of storage space cannot store the multiple different encrypted copies so as to enable one card to be decryptable by multiple locks.